Related Articles

While large suitcases and bags must be checked by airline officials for loading into the aircraft's main baggage compartment, passengers are allowed to bring certain smaller bags with them into the passenger cabin. These mainly include single bags for travelers making a short trip or smaller bags containing books, video players and other objects for occupying the passenger during the flight. The rules for these bags are made by the Transportation Security Administration (TSA), the Federal Aviation Administration (FAA) and individual air carriers.

Size

Carry-on bags must be small enough to store either in the cabin's overhead compartment or underneath the passenger's individual seat. Generally, the bag's maximum linear size (the combined height, width and length of the bag) is 45 inches. A bag 12 by 12 by 20 inches would qualify. Airports will often have bins to help measure a bag to determine if it is the right size. Travelers are allowed either one or two bags on board, depending on the individual air carrier.

Screening

All carry-on bags must be scanned through X-ray machines and are subject to search at the airport terminal checkpoints. Electronics like computers and video players must be removed from the bags and scanned by themselves. Liquids must be stored in bottles no greater than 3.4 ounces and contained in a quart-size plastic bag; this bag must also be removed from the carry-on bag and scanned separately. Baby formula and needed medicine can be brought on in larger quantities, and film greater than 800-speed can avoid the X-ray machine. These exceptions must be declared at the checkpoint

On-Board Storage/Use

Bags must be securely stored either in the overhead compartment or under the seat prior to takeoff. They are not to be taken out or opened until the captain has declared it safe to do so; this is usually declared by turning off the "Fasten Seat Belts" sign. Small electronic devices can be used during flight once it is declared safe to do so, but communication devices like cell phones must remain turned off for the duration of the flight. Once the plane begins descent, bags must again be stored until the plane has completely stopped and passengers are allowed to leave their seats.